1. Field of the Invention
The present invention relates to a coating/developing apparatus to be disposed adjacent to an immersion light exposure apparatus, and a pattern forming method for forming a predetermined resist pattern on a substrate. The immersion light exposure apparatus is arranged to subject a resist film formed on a substrate, such as a semiconductor substrate, to light exposure while immersing the resist film in a liquid. The coating/developing apparatus is arranged to apply a resist liquid onto a substrate to form a resist film, and to perform a developing process on the resist film after it is subjected to the immersion light exposure process by the immersion light exposure apparatus.
2. Description of the Related Art
In the process of manufacturing semiconductor devices, photolithography techniques are used for forming circuit patterns on semiconductor wafers. Where a circuit pattern is formed by use of photolithography, the process steps are performed, as follows. Specifically, a resist liquid is first applied to a semiconductor wafer to form a resist film. Then, the resist film is irradiated with light to perform light exposure on the resist film in accordance with the circuit pattern. Then, the resist film is subjected to a developing process.
In recent years, the integration degree of semiconductor devices becomes increasingly higher to improve the operation speed and so forth. Accordingly, photolithography techniques are required to increase the miniaturization level of circuit patterns formed on semiconductor wafers. As a photolithography technique for realizing a high resolution of a 45-nm node level, there has been proposed the following immersion light exposure (for example, see U.S. Patent Application Publication No. US 2006/0231206 A1). In this immersion light exposure, a liquid, such as purified water, having a refractive index higher than air is supplied between the semiconductor wafer and light exposure projection lens. The wavelength of light radiated from the projection lens is shortened by means of the refractive index of the liquid, so that the line width obtained by the light exposure is decreased.
In general, where a circuit pattern is formed by such immersion light exposure, liquid deposited on a wafer during the immersion light exposure may bring about development defects. Accordingly, in order to remove the deposited liquid, cleaning (rinsing) is performed by use of purified water on the wafer processed by immersion light exposure, then the wafer W is rotated by a spin chuck or the like in a horizontal state to perform throwing-off and drying of liquid.
However, where the throwing-off and drying process is performed by rotation, liquid droplets may remain and/or traces of remaining liquid droplets (stains, water marks, and so forth) may be generated on the wafer.
Further, where the throwing-off and drying process is performed by rotation, it is difficult to remove liquid components impregnated in films, such as a resist film, on the wafer.